Guess the Number -Math riddle

20.Math Riddles

Can you solve this?

Guess_the_Number_Riddle_20-math-riddles

A.18
B.19
C.88
D.96

Explanation :  

The pattern is,
First Method,
1*4+1  = 5
2*5+2  = 12
3*6+3  = 21
11*8+8 = 96

Second Method,
1+4=5
2+5=12
3+6=21
4+7=32
5+8=45
6+9=60
7+10=77
8+11=96